Route reliability record
LGA→SDF
New York to Louisville
- Flights
- 1,062
- Period
- July 2025 to June 2026
- Distance
- 659 mi
- Carriers
- 3
This route carries a cancellation problem, not just a delay problem: 3.6% of scheduled flights never operate, against 1.8% nationally. Of the ones that do fly, about four flights in five arrive on time, worth a B− overall. The punctuality figure counts only flights that actually departed, so it flatters an operation that cancels this often. That rests on 1,062 LGA to SDF flights, with a median arrival 13 minutes early.
Best time to fly LGA to SDF: a 8am–11am departure, ideally on a Saturday. Flights in that window arrived on time 86.8% of the time and Saturday flights 88.5%, against 79.8% for the route overall.
The US average over the same twelve months is 77.6%, so there is little to separate this route from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.
Key figures
On time
79.8%
Arrivals under 15 minutes late, of 1,022 completed flights
Avg delay
75 min
Across delayed arrivals only, not all flights
Cancelled
3.58%
National rate is 1.81%
Best carrier
Republic
79.5% on time across 1,026 flights
These figures cover 1,062 flights between July 2025 and June 2026. Beyond the headline rate, 8.9% of arrivals land a full hour or more behind schedule. That is the number that wrecks a connection, and it is not visible in an on-time percentage alone.
Carrier by carrier
Which airline is most reliable on LGA to SDF
Only one carrier clears this site's 365-flight floor here, so there is no comparison to draw. The table below is the full picture.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| SkyWest Airlinesthin sample | 35 | 91.2% | 197 min | 2.86% | A |
| Republic Airways | 1,026 | 79.5% | 73 min | 3.61% | B− |
| American Airlinesthin sample | 1 | 0.0% | 109 min | 0.00% | F+ |
Flight by flight
Flights on LGA to SDF
The flight numbers below flew this route at least 250 times in the period, busiest first. Each has its own record, with its schedule and delay causes.
Best ways to make this trip
The most reliable ways to fly New York to Louisville
Every airline on this route and on the routes between nearby airports, ranked by how often a scheduled flight actually operated and arrived on time. 1 of the top 2 use a different airport at one end.
| Option | Airline | Success | On time | Cancelled | Best departure | Most punctual flight |
|---|---|---|---|---|---|---|
| 1. EWR → SDFNewark to Louisville | Republic Airways | 78.0% | 81.9% | 4.80% | 8am–11am, Thu (route) | YX 3609 20:29 |
| 2. LGA → SDFNew York to Louisville | Republic Airways | 76.6% | 79.5% | 3.61% | 8am–11am, Sat (route) | YX 5643 08:30 |
Success is the share of scheduled flights that operated and arrived less than 15 minutes late, so a cancelled flight counts against it. “(route)” means the best time comes from every carrier on the route rather than this airline alone.
Departure window
The best time of day to leave
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 19 points, against half a point between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am20 flights—
- 8am–11am285 flights86.8%
- 11am–2pm260 flights83.8%
- 2pm–5pm131 flights86.6%
- 5pm–8pm366 flights68.3%
- 8pm–5am—
Scale runs 60% to 90%. Rows with fewer than 30 flights show a dash.
Book the morning departure. Flights leaving between 8am–11am arrive on time 86.8% of the time, against 68.3% for the evening window. That is 19 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 5pm–8pm window is the busiest, with 366 flights scheduled in it.
Across the year
When delays peak on this route
This route's year swings by 21 points from best month to worst, which is wide. An annual average tells you very little about the week you are actually flying, so read the strip rather than the headline if your dates are fixed.
July is the worst month at 68.8% on time, 21 points below August, the best at 89.8%. Summer afternoon convection and peak-season schedules land on the same weeks every year, so this is a pattern you can book around rather than a run of bad luck. May was the busiest month here, with 115 flights.
Across the week, Saturday is the strongest day at 88.5% on time and Sunday the weakest at 74.7%. 14 points is a smaller lever than departure hour, but it is free.
Delay causes
Why this route gets delayed
Carriers report a reason for every delay minute they cause, in five DOT categories. The split below is by minutes, not by number of flights, so a handful of very long weather delays weighs as much as many short ones. It covers 15,000 reported delay minutes.
- 38%Late-arriving aircraft
- 26%National Airspace System
- 25%Carrier
- 11%Extreme weather
Extreme weather accounts for 11% of delay minutes, well above the single-digit share typical across the system. Weather delays are lumpy: they arrive as whole bad days rather than as a steady drag, so the monthly strip above is the more useful view of the risk. The national share is 6%, so this operation carries roughly 1.8 times the usual weather exposure. The split is drawn from 15,397 reported delay minutes.
38% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. That is a cascade, and cascades start small and grow through the day. Across 15,000 reported delay minutes here, that single category outweighs weather by 3 to one. It is the strongest argument for booking the first departure of the morning, when the aircraft has been sitting at the gate overnight with nothing to inherit.
Cancellations run at 3.58%, against 1.81% nationally. That is about one flight in 30 cancelled outright. A cancelled flight is invisible in every on-time figure on this page, so the punctuality numbers above describe only the flights that actually operated.
Connections and stage length
What a delay here actually costs
8.9% of arrivals land an hour or more late, close to the national 8.1%. That is the figure that decides a connection, and it says a 60 to 75 minute layover is reasonable here while anything under 45 minutes is a bet. Most delays on this route last a little over an hour, which a normal layover absorbs.
The 659 miles between these two airports put this in the middle of the US network, around two and a half to three hours of block time. That is enough cruise to absorb a ten-minute late pushback and not enough to absorb thirty. It is also long enough that the aircraft usually flies three or four legs a day rather than six, which slows how fast delay compounds.
The return leg is a different operation and performs like one: it runs 83.1% on time across 1,063 flights, 3 points above this direction. Departure banks, aircraft rotations and the congestion at each end all differ, so scoring the two directions together would average away a real 3 points of difference.
One caution: this is a thin sample. 1,062 flights over twelve months is enough to clear this site's floor but not enough to pin the rate down tightly, and a single bad week moves it by more than a point. Treat the grade as a rough reading.
Work out the risk of missing a connection in SDF after this flight
What to do with this
Booking this route
Put together: the delay figures matter less here than the 3.58% cancellation rate. A late arrival costs you a little over an hour; a cancelled flight costs you the day. Book the 8am–11am departure so there is still a schedule behind you if it goes wrong, and treat a same-day connection as optimistic. 1,022 completed flights over 12 months sit behind that.
Common questions
LGA to SDF questions
How often is LGA to SDF delayed?
About one flight in five arrives at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 20.2% of the 1,062 flights in this analysis, against 22.4% nationally. Delayed flights are late by a little over an hour on average.
How reliable is LGA to SDF compared with the rest of the country?
79.8% of flights arrive on time here against a national 77.6%, a difference of 2 points in its favour. That is worth a B− on this site's grading scale.
What time of day has the fewest delays on LGA to SDF?
The 8am–11am departure window is the strongest at 86.8% on time. The 5pm–8pm window is the weakest at 68.3%, 19 points behind. Later departures inherit delays from earlier flights the same aircraft has already flown, which is why the curve slopes the way it does.
How bad are July delays on LGA to SDF?
July is the weakest month at 68.8% on time, compared with 89.8% in August. Across the year that is 21 points between the best and worst months. Moving flexible dates out of that month is one of the few things that reliably helps.
Related
Where to go next
- SDF to LGA — the return legseparate record
- LaGuardia (LGA) delay statistics
- LGA to ORD, a related route67.3%
- ORD to SDF, a related route75.3%
- LGA to ATL, a related route76.6%
- SkyWest Airlines on-time record91.2%
- Republic Airways on-time record79.5%
- American Airlines on-time record0.0%
- The US routes with the most cancellations
- Why the first flight of the morning is statistically safest
Direction matters. LGA to SDF and SDF to LGA are scored separately because they are separate operations, with different departure banks and different aircraft. Compare the return leg.
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Source: US DOT Bureau of Transportation Statistics, on-time performance data, July 2025 to June 2026. Last updated 15 September 2026; recomputed monthly. How this data is collected.